@article{oai:nfu.repo.nii.ac.jp:00001801, author = {諏訪, 兼位 and 伊藤, 明男 and 田中, 吉治 and 友房, 克文 and 坂野, 皓 and 小野, 淳 and Suwa, Kanenori and Itoh, Akio and Tanaka, Yoshiharu and Tomofusa, Katsufumi and Sakano, Hiroshi and Ono, Jun}, journal = {日本福祉大学情報社会科学論集, Journal of social and information sciences, Nihon Fukushi University}, month = {Dec}, note = {Geological, mineralogical and geochemical features of rock salt from Lake Asele in Danakil Depression are described and discussed in this paper. The rock salt samples described were collected from Lake Asele by H. Sakano in March, 1998. Lake Asele is located in the Danakil Depression, which occupies a northern part of the Afar Depression. The Afar Depression is a triple junction of the three rifts : Red Sea rift, Gulf of Aden rift and Ethiopian rift. Quaternary marine deposits are found to occur in and around Lake Asele area, and the deposits are mainly composed of evaporites such as rock salt. Quaternary volcanic rocks are also found to occur in and around Lake Asele area. Volcanic activity such as fumarolic gas activity is still active. Rock salt for medical use occurs at "Red Salt Hills", in the northern end of Lake Asele. The rock salt for medical use is brown to pale brown in colour and is affected intensively by the fumarolic gas activity. Common rock salt occurring in and around Lake Asele area consists mainly of halite(NaCl) with minor amounts of gypsum(CaSO4・2H2O). The rock salt for medical use occurring at the "Red Salt Hills" consists mainly of halite(NaCl) with minor amounts of anhydrite (CaSO4). It is noticeable that sulfate in the common rock salt contains crystal water and sulfate in the rock salt for medical use contains no crystal water. This transformation from gypsum to anhydrite is considered to be dehydration by heating of volcanic activity. The rock salt for medical use is more rich in Ca and SO4 than the common rock salt, and these components are considered to be supplied with the active fumarolic gas.}, pages = {23--31}, title = {エチオピア ダナキル凹地 アサレ湖の岩塩}, volume = {2}, year = {1998}, yomi = {スワ, カネノリ and イトウ, アキオ and タナカ, ヨシハル and トモフサ, カツフミ and サカノ, ヒロシ and オノ, ジュン} }